Fuel tank

ABSTRACT

A fuel tank includes an inner surface, an engaged portion protruding from the inner surface, an in-tank component part including an accommodation for accommodating the engaged portion, and an engaging portion engaging with the engaged portion and placed in the accommodation of the in-tank component part. The fuel tank can inhibit the fastening force acting between itself and the in-tank component part from degrading.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a fuel tank. In particular, it relates to a structure for installing in-tank component parts, for instance, such as valves to be installed to the inside of fuel tanks, to the fuel tanks.

2. Description of the Related Art

For example, as disclosed in Japanese Unexamined Patent Publication (KOKAI) NO.2001-41,124, an in-tank component part, such as a valve, is installed to the inner surface of a fuel tank by way of a connecting member, such as a bracket. However, the number of the fuel tank's component parts has increased by the number of the connecting members disposed.

Hence, National Publication of the Translated Version of PCT Application No. 2003-517,142 discloses a valve which is installed directly to a fuel tank by press-in fitting. FIG. 17 illustrates a cross-sectional view of the valve described in the publication. The cross-sectional view is taken along the up/down direction. As shown in the drawing, a projection 102 protrudes from a top wall 101 of a fuel tank 100 toward the inside of the fuel tank 100. On the other hand, a cylinder-shaped rib 105 protrudes from a top wall 104 of a valve 103. A pressing claw 106 which goes around the inner periphery of the rib 105 completely protrudes from the top-end inner peripheral surface of the rib 105 toward the inner peripheral side of the rib 105. The projection 102 is fitted relatively into the inner peripheral side of the pressing claw 106. Note that the inside diameter of the pressing claw 106 is designed to be smaller than the outside diameter of the projection 102. Accordingly, the pressing claw 106 presses against to the outer peripheral surface of the projection 102 after fitting the projection 102 into the pressing claw 106. That is, the valve 103 is installed to the fuel tank 100 by press-in fitting the projection 102 relatively into the inner peripheral side of the pressing claw 106.

There is a fear, however, that radially-enlarging strain resides in the rib 105 after installing the valve 103 to the fuel tank 100 as disclosed in National Publication of the Translated Version of PCT Application No. 2003-517,142. As a result, the pressing force exerted by the pressing claw 106 to the outer peripheral surface of the projection 102 might degrade.

In other words, when installing the valve 103 to the fuel tank 100, the rib 105 deforms to radially enlarge as the projection 102 is fitted into the pressing claw 106 by press-in fitting. In this instance, a pressing force is applied to the projection 102 to radially contract the projection 102. The pressing force acts all around the projection 102 entirely. Accordingly, a first pressing force (e.g., a force F1 of FIG. 17) applied to the projection 102 in an arbitrary direction has been canceled by an opposite second pressing force (e.g., a force F2 of FIG. 17) acting to the projection 102 at a diagonally opposite position with respect to the first pressing force. Consequently, the pressing forces have been canceled all around the projection 102 completely. Thus, when fitting the projection 102 into the pressing claw 106 by press-in fitting, the projection 102 hardly deforms. That is, when installing the valve 103 to the fuel tank 100, only the rib 105 deforms. Therefore, it is necessary to radially enlarge the rib 105 by a greater magnitude in order to apply a desired pressing force to the projection 102 securely. However, when the rib 105 is radially enlarged beyond the elastic limit, radially-enlarging strain has resided in the rib 105. As a result, the pressing force exerted by the pressing claw 106 to the outer peripheral surface of the projection 102 has degraded by the strain.

Moreover, when the fuel tank 100 disclosed in National Publication of the Translated Version of PCT Application No. 2003-517,142 is subjected to a radial swinging force (e.g., a force F3 of FIG. 17) which swings the valve 103 radially, only the pressed portion between the pressing claw 106 and the outer peripheral surface of the projection 102 is subjected to the radial swinging force. Specifically, the radial swinging force acted onto the pressed portion intensively. When the radially swinging force results in strain residing in the pressing claw 106 or in the outer peripheral surface of the projection 102, there arises a fear of degrading the pressing force exerted by the pressing claw 106 to the outer peripheral surface of the projection 102. Thus, the pressing force might degrade not only when installing the valve 103 to the fuel tank 100 but also after installing the valve 103 thereto.

SUMMARY OF THE INVENTION

The present invention has been developed and completed in view of such circumstances. It is therefore an object of the present invention to provide a fuel tank which can inhibit a fastening force acting between itself and in-tank components from degrading.

A fuel tank according to the present invention can solve the aforementioned problems, and comprises:

-   -   an inner surface;     -   an engaged portion protruding from the inner surface;     -   an in-tank component part comprising an accommodation for         accommodating the engaged portion; and     -   an engaging portion engaging with the engaged portion, and         placed in the accommodation of the in-tank component part.

Specifically, in accordance with the present invention, the in-tank component part is installed to the present fuel tank by engaging the engaged portion disposed on the present fuel tank side with the engaging portion disposed on the in-tank component part side. In this instance, the in-tank component part comprises the accommodation, and the engaging portion is placed in the accommodation. Thus, the engaging portion engages with the engaged portion in the accommodation.

In accordance with the present invention, the engagement formed by the engaging portion and engaged portion is accommodated in the accommodation. That is, the accommodation reinforces the engagement. Accordingly, even when the present fuel tank is subjected to swinging forces to swing the in-tank component part, not only the engagement but also the accommodation can receive the swinging forces in a dispersed manner. Consequently, strain is less likely to reside in the engaging portion and engaged portion. Therefore, the present fuel tank can inhibit a fastening force acting between itself and the in-tank component part from degrading.

Moreover, when the in-tank component part or the accommodation is less likely to swell than the present fuel tank or the engaged portion is, the engaged portion swells in the accommodation after the in-tank component part is installed to the present fuel tank, specifically after the present fuel tank is filled up with a fuel. As a result, the engaged portion presses against the engaging portion placed in the accommodation. Thus, the present fuel tank can inhibit the fastening force from degrading in the installation of the in-tank component part, and can even raise the fastening force after the installation.

It is preferable to arrange the present fuel tank so that both of the engaged portion and the engaging portion can deform elastically to engage the engaging portion with the engaged portion; and the in-tank component part can be installed to the fuel tank with the engaged portion accommodated in the accommodation.

With such an arrangement, both of the engaged portion and the engaging portion deform in the installation of the in-tank component part to the present fuel tank. Accordingly, strain is much less likely to reside in the engaged portion and engaging portion after the installation. Consequently, it is possible to further inhibit the fastening force acting between the present fuel tank and the in-tank component part from degrading.

It is preferable to arrange the present fuel tank so that the engaged portion can comprise an engaged rib through which an engaged hole is bored; and the engaging portion can comprise an engaging claw engaging with the engaged hole. Note that the engaged rib has a simpler superficial construction than the engaging claw does. Accordingly, such an arrangement can make it more likely to integrally form the engaged rib with the present fuel tank by molding, for example.

It is preferable to arrange the present fuel tank so that the accommodation of the in-tank component part can comprise a thinned portion for making it easier to accommodate the engaged portion therein. Such an arrangement can expand the accommodation space in the accommodation by the space produced by the thinned portion. Accordingly, the engaged portion is more likely to come into the accommodation.

It is preferable to arrange the present fuel tank so as to further comprise an insertion tab fitted into the accommodation of the in-tank component part, wherein:

-   -   the insertion tab is fitted temporarily into the accommodation         with an accommodation allowance for the engaged portion left to         the accommodation in a first step;     -   the engaging portion engages with the engaged portion, and the         in-tank component part is installed temporarily to the fuel tank         with the engaged portion accommodated in the accommodation in a         second step; and     -   the temporarily fitted insertion tab is further fitted fully         into the accommodation, and a surplus allowance in the         accommodation, the surplus allowance resulting from the         accommodation allowance, disappears to fully install the in-tank         component part to the fuel tank in a third step.

The term, “surplus allowance,” herein means a space for the insertion tab, that is, the “surplus allowance” is the difference between the accommodation allowance and a space for the engaged portion. Specifically, the “surplus allowance” is an excessive allowance being present in the accommodation allowance after the engaged portion is accommodated in the accommodation.

Specifically, with such an arrangement, the in-tank component part is installed to the present fuel tank stepwise. That is, the in-tank component part is installed temporarily to the present fuel tank, and is then fully installed to it.

In the first step, the insertion tab is fitted into the accommodation while securing an accommodation allowance for the engaging portion. That is, the insertion tab is fitted temporarily into the accommodation of the in-tank component part. In the second step, the engaging portion is engaged with the engaged portion using the accommodation allowance secured in the first step. Moreover, the engaged portion is accommodated in the accommodation. Note that, in the second step, it is possible to engage the engaging portion with the engaged portion with ease relatively, because the accommodation allowance has been secured in advance. The in-tank component part is installed temporarily to the present fuel tank by the engagement between the engaging portion and the engaged portion. In the third step, the insertion tab is further fitted into the accommodation until the surplus allowance disappears, surplus allowance which results from the accommodation allowance. In other words, the insertion tab is fitted fully into the accommodation. When the insertion tab is fully fitted into the accommodation, the surplus allowance disappears from the accommodation. To put it differently, the play for the engaged portion disappears from the accommodation. Accordingly, rattling diminishes between the engaging portion and the engaged portion. Moreover, the fastening force rises between the engaging portion and the engaged portion. Consequently, the in-tank component part is installed fully to the present fuel tank.

Thus, the arrangement makes it possible to temporarily install the in-tank component part to the present fuel tank and then to fully install it thereto. After the temporary installation (or the second step), the in-tank component part is installed temporarily to the present fuel tank by its own fastening force. Accordingly, even when the in-tank component part is suspended inside the present fuel tank, it is not necessary for an operator to support the in-tank component part after the temporary installation. Consequently, the arrangement can be applied appropriately to in-tank component parts with a relatively large volume or in-tank component parts to be suspended in fuel tanks, because it improve the operability.

In accordance with another aspect of the present invention, the aforementioned problems can be solved as well. A fuel tank comprises:

-   -   an inner surface;     -   an engaged portion protruding from the inner surface;     -   an in-tank component part; and     -   an engaging portion disposed in the in-tank component part, and         engaging inward with an outer periphery of the engaged portion         from an outer peripheral side to an inner peripheral side,         wherein:     -   both of the engaged portion and the engaging portion deform         elastically to engage the engaging portion with the engaged         portion, thereby installing the in-tank component part to the         fuel tank.

In the another aspect of the present invention, both of the engaged portion and the engaging portion deform in the installation of the in-tank component part to the present fuel tank. Accordingly, strain is much less likely to reside in the engaged portion and engaging portion after the installation. Consequently, such an arrangement according to the another aspect of the present invention makes it possible to further inhibit the fastening force between the present fuel tank and the in-tank component part from degrading in the installation.

Moreover, when the in-tank component part is less likely to swell than the present fuel tank is, the in-tank component part or the engaging portion is less likely to be swollen by fuels. On the other hand, the present fuel tank or the engaged portion is likely to be swollen by fuels. In view of these, in the present fuel tank according to the another aspect of the present invention, the engaged portion is disposed on an inner peripheral side, and the engaging portion is disposed on an outer peripheral side, respectively. Accordingly, in the present fuel tank after the installation of the in-tank component part, specifically after being filled up with a fuel, the engaging portion regulates the engaged portion, which expands radially outward from the inner peripheral side to the outer peripheral side, inward from the outer peripheral side to the inner peripheral side. As a result, the engaged portion presses against the engaging portion radially. Thus, the present fuel tank can inhibit the fastening force from degrading in the-installation of the in-tank component part, and can even raise the fastening force after the installation.

It is preferable to arrange the present fuel tank according to the another aspect of the present invention so that the engaged portion can comprise an engaged rib through which an engaged hole is bored; and the engaging portion can comprise an engaging claw engaging with the engaged hole. Note that the engaged rib has a simpler superficial construction than the engaging claw does. Accordingly, such an arrangement can make it more likely to integrally form the engaged rib with the present fuel tank by molding, for example.

All in all, the present fuel tank can inhibit the fastening force acting between the engaging portion and the engaged portion from degrading.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of the present invention and many of its advantages will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings and detailed specification, all of which forms a part of the disclosure.

FIG. 1 is an exploded view of a fuel tank according to Example No. 1 of the present invention in which a fuel shut-off valve is installed.

FIG. 2 is an appearance view of the fuel shut-off valve.

FIG. 3 is a cross-sectional view of the fuel shut-off valve taken along the up/down direction.

FIG. 4 is a cross-sectional view of the fuel shut-off valve taken along the chain line “4”-“4” of FIG. 3.

FIG. 5 is a perspective view for illustrating how an accommodation and an engaged rib are placed in the present fuel tank according to Example No. 1 when the fuel shut-off valve is installed to the present fuel tank.

FIG. 6 is a cross-sectional view for illustrating how the accommodation and the engaged rib are placed in the present fuel tank according to Example No. 1 in the installation of the fuel shut-off valve to the present fuel tank.

FIG. 7 is a perspective view for illustrating how the accommodation and the engaged rib are placed in the present fuel tank according to Example No. 1 after the installation of the fuel shut-off valve to the present fuel tank.

FIG. 8 is an appearance view of a fuel tank according to Example No. 2 of the present invention in which a valve module is installed.

FIG. 9 is an enlarged perspective view of an engagement between the present fuel tank according to Example No. 2 and the valve module.

Fig. 10 is an enlarged cross-sectional view of the engagement between the present fuel tank according to Example No. 2 and the valve module.

FIG. 11 is an exploded perspective view of the engagement between the present fuel tank according to Example No. 2 and the valve module.

FIG. 12 is an exploded cross-sectional view of the engagement between the present fuel tank according to Example No. 2 and the valve module.

FIG. 13 is an enlarged perspective view of the engagement between the present fuel tank according to Example No. 2 and the valve module in a first step.

FIG. 14 is an enlarged cross-sectional view of the engagement between the present fuel tank according to Example No. 2 and the valve module in the first step.

FIG. 15 is an enlarged perspective view of the engagement between the present fuel tank according to Example No. 2 and the valve module in a second step.

FIG. 16 is an enlarged cross-sectional view of the engagement between the present fuel tank according to Example No. 2 and the valve module in the second step.

FIG. 17 is a cross-sectional view of the conventional fuel tank, to which a valve is installed, taken along the up/down direction.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Having generally described the present invention, a further understanding can be obtained by reference to the specific preferred embodiments which are provided herein for the purpose of illustration only and not intended to limit the scope of the appended claims.

EXAMPLES Example No. 1

A fuel tank according to Example No. 1 of the present invention comprises a fuel shut-off valve which is installed to the top wall.

First, the arrangement of a fuel tank according to Example No. 1 of the present invention will be hereinafter described in detail. FIG. 1 illustrates an exploded perspective view of the fuel tank according to Example No. 1 in which a fuel shut-off valve is installed. FIG. 2 illustrates an appearance view of the fuel shut-off valve. FIG. 3 illustrates a cross-sectional view of the fuel shut-off valve taken along the up/down direction. FIG. 4 illustrates a cross-sectional view of the fuel shut-off valve taken along the chain line “4”-“4” of FIG. 3.

A fuel tank 9 is made of high-density polyethylene (hereinafter abbreviated to as “HDPE”), and comprises a top wall 90 from which engaged ribs 91 a, 91 b, 91 c protrude. A fuel shut-off valve 1 is installed to the engaged ribs 91 a, 91 b, 91 c. Note that the present in-tank component part includes the fuel shut-off valve 1. The fuel shut-off valve 1 comprises an upper case 2, a lower case 3, a bottom 4, and a float 5.

The upper case 2 is made of polyoxymethylene (hereinafter abbreviated to as “POM”), and is formed as a bottomed cylinder shape which opens downward. Accommodations 20 a, 20 b, 20 c extend from the bottom end of the upper case 2 in a radially enlarging direction. The accommodation 20 a is formed as a substantially “U”-shaped cross section which opens upward. An engaging claw 201 a whose cross section is formed as a triangle shape protrudes from a top-end inner surface of an outer peripheral wall 200 a of the accommodation 20 a. Moreover, as shown in FIG. 4, paired rotation-stopper ribs 205 a, 205 a erect from the peripheral opposite ends of the outer peripheral wall 200 a. On the other hand, a thinned portion 203 a is formed in an inner surface of an inner peripheral wall 202 a of the accommodation 20 a. In addition, an accommodation chamber 204 a is demarcated between the outer peripheral wall 200 a and the inner peripheral wall 202 a. As shown in FIG. 3, the engaged rib 91 a is accommodated into the accommodation chamber 204 a downward from the upper side to the lower side. The engaging claw 201 a engages with an engaged hole 910 a which is bored through the engaged rib 91 a. Note that the accommodations 20 b, 20 c are constructed in the same manner as the accommodation 20 a. Therefore, the construction of the accommodations 20 b, 20 c will not be described repeatedly.

As shown in FIG. 4, the accommodations 20 a, 20 b, 20 c are scattered at predetermined angular intervals in the substantially identical circumferential direction of the upper case 2. Specifically, an angle α intervening between the engaging claw 201 a of the accommodation 20 a and the engaging claw 201 b of the accommodation 20 b is designed to be 115°. Moreover, an angle β intervening between the engaging claw 201 b of the accommodation 20 b and the engaging claw 201 c of the accommodation 20 c is designed to be 130°. In addition, an angle γ intervening between the engaging claw 201 c of the accommodation 20 c and the engaging claw 201 a of the accommodation 20 a is designed to be 115°. As shown in FIG. 1, the engaged ribs 91 a, 91 b, 91 c face the engaging claws 201 a, 201 b, 201 c in the up/down direction, respectively. Moreover, as described above, the engaging ribs 201 a, 201 b, 201 c engage with the engaged holes 910 a, 910 b, 910 c of the engaged ribs 91 a, 91 b, 91 c, respectively. Thus, the upper case 2, i.e., the fuel shut-off valve 1, is installed to the fuel tank 9.

The lower case 3 is made of POM, and is formed as a bottomed cylinder shape which opens downward. As illustrated in FIG. 3, the lower case 3 is welded to the opening periphery of the upper case 2. A float chamber 31 is demarcated inside the lower case 3. Moreover, an inter-case communication hole 30 for communicating the lower case 3 with the upper case 2 is bored through at the substantial center of a top wall of the lower case 3. The float chamber 31 communicates with the inside of the upper case 2 by way of the inter-case communication hole 30. In addition, a cylinder-shaped relief tube 32 penetrates through the top wall of the lower case 3. The float chamber 31 communicates with the inside of the upper case 2 by way of the relief tube 32. A radially-reducing valve seat 320 is formed at the lower end of the relief tube 32. A ball-shaped valve element 321 is disposed on the radially-reducing valve seat 320. A relief spring 322 intervenes between the ball-shaped valve element 321 and the top wall of the upper case 2. The urging force of the relief spring 321 pushes the ball-shaped valve element 321 against the radially-reducing valve seat 320. A cylinder-shaped port 33 protrudes from an outer peripheral surface of a side peripheral wall of the lower case 3 slightly downward in a radially enlarging direction. A hose (not shown), which communicates with a canister, is fitted around the outer-peripheral end of the port 33. On the other hand, the inner-peripheral end of the port 33 communicates with the inside of the upper case 2. Thus, as shown in FIG. 3, the canister communicates with the inside of the upper case 2 by way of the port 33. Moreover, as illustrated in FIGS. 1 and 2, engaged recesses 34 are made in the outer peripheral surface of the side peripheral wall of the lower case 3. The engaged recesses 34 disposed at angular intervals of 90° in the circumferential direction of the lower case 3 in a quantity of four in total.

The bottom 4 is made of POM, and is formed as a bottomed cylinder shape which opens upward. As illustrated in FIGS. 1 and 2, lower-case engaging claws 40 for engaging the bottom 4 with the lower case 3 are formed in the side peripheral wall of the bottom 4. The lower-case engaging claws 40 disposed at angular intervals of 90° in the circumferential direction of the bottom 4 in a quantity of four in total. The lower-case engaging claws 40 engage with the lower periphery of the engaged recesses 34. Thus, the bottom 4 is installed to the lower periphery of the lower case 3. Then, as illustrated in FIG. 3, the bottom 4 encloses the float chamber 31. Moreover, tank communication holes 41 for communicating the float chamber 31 with the fuel tank 9 are formed in the bottom wall of the bottom 4. The float chamber 31 communicates with the inside of the fuel tank 9 by way of the tank communication holes 41. In addition, a cylinder-shaped projection 42 protrudes from an upper surface of the bottom wall of the bottom 4.

The float 5 is made of POM, and is formed as a cylinder shape in which a convexed valve element 50 protrudes from the top surface as illustrated in FIG. 3. The float 5 is accommodated in the float chamber 31. The convexed valve element 50 faces the inter-case communication hole 30 in the up/down direction. A depression 51 is made in the bottom surface of the float 5. The projection 42 of the bottom 4 is fitted into the depression 51. A float spring 420 is fitted around the projection 42. The float spring 420 urges the float 5 upward.

Next, the operations of the fuel tank 9 according to Example No. 1 with the fuel shut-off valve 1 installed will be hereinafter described. In supplying a fuel, the fuel vapor is introduced into the canister from the inside of the fuel tank 9 by way of the tank communication holes 41, the float chamber 31, the inter-case communication hole 30, the inside of the upper case 2, the inside of the port 33 and the hose as can be seen from FIG. 3. When the fuel is filled up to a predetermined liquid level, the fuel flows into the float chamber 31 from the inside of the fuel tank 9 by way of the tank communication holes 41. The buoyant force exerted by the flowing-in fuel and the urging force of the float spring 420 raise the float 5. Then, the convexed valve element 50 of the float 5 closes the inter-case communication hole 30. Thus, the fuel tank 9 inhibits the fuel from flowing out to the canister. Note that the ball-shaped valve element 321 separates from the radially-reducing valve seat 320 to rise when the pressure within the fuel tank 9 heightens excessively. Thus, the pressure within the fuel tank 9 is controlled.

Subsequently, how to install the fuel shut-off valve 1 to the fuel tank 9 according to Example No. 1 will be hereinafter described. First, the upper case 2 and the lower case 3 are welded together. Then, the lower-case engaging claws 40 are engaged with the lower periphery of the engaged recesses 34 to assemble the bottom 4 with the lower case 3. Thus, the fuel shut-off valve 1 is completed.

Thereafter, the positioning is carried out between the engaging claws 201 a, 201 b, 201 c and the engaged ribs 91 a, 91 b, 91 c. Then, the fuel shut-off valve 1 is brought closely to the top wall 90 of the fuel tank 9. FIG. 5 illustrates how the accommodation 20 a and the engaged rib 91 a are placed when the fuel shut-off valve 1 is installed to the fuel tank 9 in a perspective view. FIG. 6 illustrates how the accommodation 20 a and the engaged rib 91 a are placed when the fuel shut-off valve 1 is installed to the fuel tank 9 in a cross-sectional view. As shown in the drawings, the engaged rib 91 a curves elastically toward the inner peripheral side when the engaged rib 91 a contacts with the engaging claw 201 a. On the other hand, the engaging claw 201 a and the outer peripheral wall 200 a of the accommodation 20 a curve elastically toward the outer peripheral side. In this instance, the thinned portion 203 a is formed in the inner peripheral wall 202 a of the accommodation 20 a. Accordingly, the engaging claw 201 a and the outer peripheral wall 200 a can curve elastically toward the outer peripheral side with ease comparatively. Moreover, the accommodation chamber 204 a opens greatly by the thinned portion 203 a. Consequently, the engaged rib 91 a is likely to come into the accommodation chamber 204 a. FIG. 7 illustrates how the accommodation 20 a and the engaged rib 91 a are placed after the fuel shut-off valve 1 is installed to the fuel tank 9 in a perspective view. When the engaging claw 201 a and engaged rib 91 a slide by a predetermined distance, their restoring forces let the engaged claw 201 a engage with the engaging hole 910 a. Moreover, the engaged rib 91 a is surrounded by the outer peripheral wall 200 a, inner peripheral wall 202 a and paired rotation-stopper ribs 205 a so that engaged rib 91 a is accommodated in the accommodation chamber 204 a. Note that the accommodations 20 b, 20 b and the engaged ribs 91 b, 91 c are placed in the same manner as the accommodation 20 a and the engaged rib 91 a are placed. Therefore, the operations of the accommodations 20 b, 20 c and engaged ribs 91 b, 91 c will not be described repeatedly. Thus, the engaging claws 201 a, 201 b, 201 c engage with the engaged holes 910 a, 910 b, 910 c, respectively, so that the engaged ribs 91 a, 91 b, 91 c are accommodated in the accommodations 20 a, 20 b, 20 c, respectively. As a result, the fuel shut-off valve 1 is installed to the fuel tank 9.

Finally, the advantages effected by the fuel tank 9 according to Example No. 1 will be hereinafter described. In the. fuel tank 9, the engagements formed by the engaging claws 201 a, 201 b, 201 c and the engaged ribs 91 a, 91 b, 91 c are accommodated in the accommodations 20 a, 20 b, 20 c, respectively. That is, the accommodations 20 a, 20 b, 20 c reinforce the engagements. Accordingly, even when the fuel tank 9 is subjected to swinging forces to swing the fuel shut-off valve 1, not only the engagements but also the accommodations 20 a, 20 b, 20 c can receive the swinging forces in a dispersed manner. Consequently, strain is less likely to reside in the engaging claws 201 a, 201 b, 201 c and engaged ribs 91 a, 91 b, 91 c. Therefore, the fuel tank 9 can inhibit a fastening force acting between itself and the fuel shut-off valve 1 from degrading.

In the fuel tank 9 according to Example No. 1, both of the engaged ribs 91 a, 91 b, 91 c and the engaging claws 201 a, 201 b, 201 c deform simultaneously in the installation of the fuel shut-off valve 1 to the fuel tank 9. Accordingly, strain is much less likely to reside in the engaged ribs 91 a, 91 b, 91 c and engaging claws 201 a, 201 b, 201 c after the installation. Consequently, due to the arrangement as well, it is possible to further inhibit the fastening force acting between the fuel tank 9 and the fuel shut-off valve 1 from degrading.

In the fuel tank 9 according to Example No. 1, the engaged ribs 91 a, 91 b, 91 c, the present engaged portion, protrude from the inner surface of the top wall 90 of the fuel tank 9. The engaged ribs 91 a, 91 b, 91 c are formed as a rectangular plate shape, a simpler superficial construction. Accordingly, it is possible to mold the engaged ribs 91 a, 91 b, 91 c integrally with the fuel tank 9.

In the fuel tank 9 according to Example No. 1, as shown in FIG. 4, the intervention angle α between the engaging claw 201 a and the engaging claw 201 b is designed to be 115°. Moreover, the intervention angle β between the engaging claw 201 b and the engaging claw 201 c is designed to be 130°. In addition, the intervention angle γ between the engaging claw 201 c and the engaging claw 201 a is designed to be 115°. That is, the intervention angles α, β and the intervention angle γ are not equal to each other. Accordingly, even when an operator tries to engage the engaging claw 201 c with the engaged rib 91 a, specifically when an operator tries to install the fuel shut-off valve 1, which is swung by 115° in the clockwise direction from the disposition illustrated in FIG. 4, to the fuel tank 9, he or she cannot install the fuel shut-off valve 1 to the fuel tank 9 because the position of the engagement claw 201 b is displaced with respect to that of the engaged rib 91 c by 15° relatively. In other words, the fuel shut-off valve 1 can be installed to the fuel tank 9 only when the engagement claws 201 a, 201 b, 201 c face the engaged ribs 91 a, 91 b, 91 c in the up/down direction, respectively. Consequently, in the fuel tank 9, it is easy to position the fuel shut-off valve 1 with respect to the fuel tank 9. Therefore, there is no fear of disposing the port 33 of the fuel shut-off valve 1 with incorrect outlet angles in the installation operation. Moreover, when the width of the engaged rib 91 a is made larger than that of the engaged ribs 91 b, 91 c and the width of the accommodation 20 a (or the arc length of the outer peripheral wall 200 a) is made larger in compliance with the enlarged width of the engaged rib 91 a, it is possible to prevent wrong assembly.

In the fuel tank 9 according to Example No. 1, the thinned portions 203 a, 203 b, 203 c are disposed in the accommodations 20 a, 20 b, 20 c, respectively. Accordingly, the engagement claw 201 a and outer peripheral wall 200 a, the engagement claw 201 b and outer peripheral wall 200 b, and the engagement claw 201 c and outer peripheral wall 200 c curve elastically toward the outer peripheral side with ease comparatively when the fuel shut-off valve 1 is installed to the fuel tank 9. Moreover, the accommodation chambers 204 a, 204 b, 204 c open greatly by the thinned portions 203 a, 203 b, 203 c. Consequently, the engaged ribs 91 a, 91 b, 91 c are likely to come into the accommodation chamber 204 a, 204 b, 204 c, respectively. In addition, it is less likely to damage the engaged ribs 91 a, 91 b, 91 c, which are made of HDPE and are soft relatively.

In the fuel tank 9 according to Example No. 1, the upper case 2 (more specifically the engaging claws 201 a, 201 b, 201 c) is formed of POM. On the other hand, the fuel tank 9 (more specifically the engaged ribs 91 a, 91 b, 91 c) is formed of HDPE. Accordingly, the upper case 2 is less likely to be swollen by fuels than the fuel tank 9 is. In view of these, in the fuel tank 9, the engaged ribs 91 a, 91 b, 91 c are disposed on an inner peripheral side, and the engaging claws 201 a, 201 b, 201 c are disposed on an outer peripheral side, respectively. Consequently, in the fuel tank 9 after the installation of the fuel shut-off valve 1, specifically after being filled up with a fuel, the engaging claws 201 a, 201 b, 201 c regulate the engaged ribs 91 a, 91 b, 91 c, which expand radially outward from the inner peripheral side to the outer peripheral side, inward from the outer peripheral side to the inner peripheral side, respectively. As a result, the engaged ribs 91 a, 91 b, 91 c press against to the engaging claws 201 a, 201 b, 201 c, radially. Thus, the fuel tank 9 can even raise the fastening force acting between itself and the fuel shut-off valve 1 after the installation, specifically after being filled up with a fuel.

In the fuel tank 9 according to Example No. 1, the engaged ribs 91 a, 91 b, 91 c expand so as to bury the inside of the accommodation chambers 204 a, 204 b, 204 c, respectively, after the fuel shut-off valve 1 is installed to the fuel tank 9, specifically after the fuel tank 9 is filled up with a fuel. Due to the operation, the fuel tank 9 can further raise the fastening force acting between itself and the fuel shut-off valve 1 after the installation.

In the fuel tank 9 according to Example No. 1, after the engaging claws 201 a, 201 b, 20 c and engaged ribs 91 a, 91 b, 91 c slide by a predetermined distance in the installation of the fuel shut-off valve 1 to the fuel tank 9, their restoring forces let the engaging claws 201 a, 201 b, 201 c engage with the engaged holes 910 a, 910 b, 910 c, respectively. The clicking feel in the instant of the engagement enables an operator to confirm that the installation is completed. As a result, the installation accuracy is enhanced.

In the fuel tank 9 according to Example No. 1, the paired rotation-stopper ribs 205 a and 205 a, 205 b and 205 b, 205 c and 205 c are disposed in the accommodations 20 a, 20 b, 20 c, respectively. Hence, it is possible to inhibit the fuel shut-off valve 1 from rattling in the circumferential direction after it is installed to the fuel tank 9.

Example No. 2

A fuel tank according to Example No. 2 of the present invention comprises a valve module which is installed to the top wall.

FIG. 8 illustrates an appearance view of the fuel tank according to Example No. 2 in which a valve module is installed. FIG. 9 illustrates an enlarged perspective view of an engagement between the fuel tank and the valve module. FIG. 10 illustrates an enlarged cross-sectional view of the engagement between the fuel tank and the valve module. FIG. 11 illustrates an exploded perspective view of the engagement between the fuel tank and the valve module. FIG. 12 illustrates an exploded cross-sectional view of the engagement between the fuel tank and the valve module.

First, the arrangement of a fuel tank according to Example No. 2 of the present invention will be hereinafter described in detail. A valve module 7 is equipped with a plurality of valves (not shown). The term, “valve module,” herein means a separable component part, to be installed to an inner surface of a top wall of fuel tanks, in which independent valves, for example, those illustrated in FIGS. 1 through 4, are integrated with each other. The valve module 7 is made of POM. The present in-tank component part includes the valve module 7. As shown in the drawings, accommodations 20 are formed on the side walls of the valve module 7, and has a substantially “U”-shaped opening when viewed from the top. The accommodations 20 are scattered at predetermined intervals along the outer periphery of the valve module 7 in a quantity of eleven in total. As shown in FIG. 12, an engaging claw 201 whose cross section is formed as a triangular shape protrudes from an inner surface of an outer peripheral wall 200 of the accommodations 20. An accommodation chamber 204 is demarcated between the outer peripheral wall 200 of the accommodations 20 and the side wall of the valve module 7. An engaging claw 206 whose cross section is formed as a triangular shape and which is for engaging with a later-described insertion tab protrudes from a lower-end outer surface of the outer wall 200 of the accommodations 20.

An insertion tab 6 is made of POM, and is formed as a “U” shape in cross section. The insertion tab 6 engages with the accommodation 20 in such a state that an inner wall 63 and a rotation-stopper rib 205, which will be described later, are fitted into the accommodation chamber 204 from down below. As shown in FIGS. 9 and 10, an outer wall 60 of the insertion tab 6 is disposed on an outside of the outer peripheral wall 200 of the accommodations 20. A temporarily engaging hole 61 and a full engaging hole 62 are bored through the outer wall 60 in a neighboring manner in the up/down direction. The insertion-tab engaging claw 206 of the accommodations 20 engages with the full engaging hole 62 of the insertion tab 6. As shown in FIG. 10, a tapered surface 64 which widens outward toward the “U”-shaped opening from the inside to the outside is formed on a top end of the inner wall 63 of the insertion tab 6. Moreover, as best shown in FIG. 11, paired rotation-stopper ribs 205 protrude from opposite ends of the insertion tab 6 at the upper end of the inner wall 63.

Engaged ribs 91 protrude from the inner surface of the top wall (not shown) of the fuel tank which is made of HDPE. The engaged ribs 91 are formed as a rectangular plate shape. An engaged hole 910 is bored through the engaged ribs 91. The engaged ribs 91 are scattered at positions, which face the accommodations 20 in the up/down direction, in a quantity of eleven in total. The engaged rib 91 is accommodated in the accommodation chamber 204 of the accommodations 20. Specifically, the engaged rib 91 is accommodated between the inner wall 63 of the insertion tabs 6 and the outer peripheral wall 200 of the accommodations 20. The engaged hole 910 of the engaged ribs 91 engages with the engaging claw 201 of the accommodations 20 facing the engaged ribs 91. The engagement installs the valve module 7 to the top wall of the fuel tank.

Subsequently, how to install the valve module 7 to the fuel tank according to Example No. 2 will be hereinafter described. In a first step, the insertion tab 6 is fitted temporarily into the accommodation 20 from down below as shown with the blank arrow of FIGS. 11 and 12. FIG. 13 illustrates an enlarged perspective view of the engagement between the fuel tank and the valve module 7 in the first step. FIG. 14 illustrates an enlarged cross-sectional view of the engagement between the fuel tank and the valve module 7 in the first step. As shown in the drawings, the inner wall 63 and rotation-stopper ribs 205 of the insertion tab 6 are fitted temporarily into the accommodation chamber 204 of the accommodation 20 from down below. Then, the insertion-tab engaging claw 206 of the accommodation 20 is engaged with the temporarily engaging hole 61 of the insertion tab 6. Thus, the insertion tab 6 is engaged temporarily with the accommodation 20. Note that an accommodation allowance 207 for accommodating the engaged rib 91 is secured between the tapered surface 64 and the outer peripheral wall 200 in the accommodation chamber 204 as illustrated in FIG. 14.

In a second step, the accommodation 20 engaged temporarily with the insertion tab 6 is brought closer to the engaged rib 91 from down below. Then, the engaged rib 91 is accommodated in the accommodation chamber 204. In this instance, the engaging claw 201 contacts with the engaged rib 91. As shown in FIG. 14, the contact curves the engaging claw 201 and outer peripheral wall 200 elastically toward the outer peripheral side. On the other hand, the contact curves the engaged rib 91 elastically toward the inner peripheral side. The curved engaged rib 91 passes the accommodation allowance 207 while sliding on the engaging claw 201, and is accommodated in the accommodation chamber 204. FIG. 15 illustrates an enlarged perspective view of the engagement between the fuel tank and the valve module 7 in the second step. FIG. 16 illustrates an enlarged cross-sectional view of the engagement between the fuel tank and the valve module 7 in the second step. As shown in the drawings, the elastic restoring force of the engaging claw 201 engages the engaging claw 201 with the engaged hole 910. When all of the engaging claws 201 engage with the engaged holes 910 facing the engaging claws 201, the valve module 7 is installed temporarily to the fuel tank.

In a third step, the insertion tab 6 is pushed up further upward. That is, the insertion tab 6 is fitted fully into the accommodation chamber 204. The fully-fitted insertion tab 6 buries a surplus allowance 208 between the tapered surface 64 and the engaged rib 91 b in the accommodation chamber 204 as illustrated in FIG. 16. Moreover, the insertion-tab engaging claw 206 moves relatively from the temporarily engaging hole 61 to the full engaging hole 62. Thus, the valve module 7 is installed fully to the fuel tank. Specifically, the accommodations 20, the insertion tabs 6 and the engaged ribs 91 are put into the assembled state as illustrated in FIGS. 9 and 10.

Finally, the advantages effected by the fuel tank according to Example No. 2 will be hereinafter described. The fuel tank produces the advantages in the same manner as the fuel tank 9 according to Example No. 1. In the second step, the engaged ribs 91 are guided into the accommodation chambers 204 utilizing the accommodation allowances 207 which have been secured in the first step. Accordingly, the engagement claws 201 can be engaged with the engaged holes 910 with ease comparatively. In the third step, the fully-fitted insertion tabs 9 make the surplus allowances 208 disappear from the accommodation chambers 204. That is, the play for the engaged ribs 91 disappear from the accommodation chambers 204. Consequently, rattling diminishes between the engaging claws 201 and the engaged holes 910. In other words, the valve module 7 is less likely to rattle in the fuel tank. Moreover, the fastening force rises between the engaging claws 201 and the engaged holes 910.

Note that the outer wall 60 of the insertion tabs 6 reinforces the outer peripheral wall 200 and engaging claw 201 of the accommodations 20. Accordingly, it is possible to further inhibit the fastening force between the accommodations 20 and the engaged ribs 91 from degrading. Moreover, the tapered surface 64 is formed on the top end of the inner wall 63 of the insertion tabs 6. Consequently, it is more likely to guide the engaged ribs 91 into the accommodation chambers 204.

Note that, after the temporary installation (or the second step), the valve module is installed temporarily to the fuel tank by its own fastening force. Accordingly, it is not necessary for an operator to support the valve module 7 after the temporary installation. Consequently, the fuel tank according to Example No. 2 improves the operability in the installation of the valve module 7.

Modified Versions

Heretofore, a few of the embodiment modes of the present fuel tank are described. However, the embodiment modes are not limited to the above-described embodiment modes particularly. It is possible to perform the present fuel tank in various modified embodiment modes or improved embodiment modes which one of ordinary skill in the art can carry out.

For example, the engaging claws 201 a, 201 b, 201 c or 201 and the engaged holes 910 a, 910 b, 910 c or 910 can be disposed inversely to the disposition described in Example Nos. 1 and 2. Namely, the engaging claws can be disposed in fuel tanks, and the engaged holes can be disposed in in-tank component parts. Moreover, in Example Nos. 1 and 2, the fuel tank 9 is made of HDPE, and the fuel shut-off valve 1 and the valve module 7 (i.e., the in-tank component part) are made of POM. However, the materials for making the component parts are not limited in particular. In addition, the shapes of the engaging portion and engaged portion are not necessarily limited to the above-described shapes.

Having now fully described the present invention, it will be apparent to one of ordinary skill in the art that many changes and modifications can be made thereto without departing from the spirit or scope of the present invention as set forth herein including the appended claims. 

1. A fuel tank, comprising: an inner surface, an engaged portion protruding from the inner surface; an in-tank component part comprising an accommodation for accommodating the engaged portion; and an engaging portion engaging with the engaged portion, and placed in the accommodation of the in-tank component part.
 2. The fuel tank set forth in claim 1, wherein: both of the engaged portion and the engaging portion deform elastically to engage the engaging portion with the engaged portion; and the in-tank component part is installed to the fuel tank with the engaged portion accommodated in the accommodation.
 3. The fuel tank set forth in claim 1, wherein: the engaged portion comprises an engaged rib through which an engaged hole is bored; and the engaging portion comprises an engaging claw engaging with the engaged hole.
 4. The fuel tank set forth in claim 1, wherein the accommodation of the in-tank component part comprises a thinned portion for making it easier to accommodate the engaged portion therein.
 5. The fuel tank set forth in claim 1 further comprising an insertion tab fitted into the accommodation of the in-tank component part, wherein: the insertion tab is fitted temporarily into the accommodation with an accommodation allowance for the engaged portion left to the accommodation in a first step; the engaging portion engages with the engaged portion, and the in-tank component part is installed temporarily to the fuel tank with the engaged portion accommodated in the accommodation in a second step; and the temporarily fitted insertion tab is further fitted fully into the accommodation, and a surplus allowance in the accommodation, the surplus allowance resulting from the accommodation allowance, disappears to fully install the in-tank component part to the fuel tank in a third step.
 6. The fuel tank set forth in claim 1, wherein the engaged portion is disposed on an inner peripheral side with respect to the engaging portion.
 7. The fuel tank set forth in claim 1, wherein the engaging portion is composed of a material whose fuel-swelling property is less than that of a material composing the engaged portion.
 8. The fuel tank set forth in claim 1, wherein the engaged portion is formed as a rectangular plate shape, and the accommodation is formed as a “U”-shaped cross section.
 9. The fuel tank set forth in claim 1, wherein the accommodation further comprises paired rotation-stopper ribs.
 10. The fuel tank set forth in claim 1 comprising a plurality of pairs of the engaged portion and the engaging portion engaging with engaged portion, the pairs disposed at angular intervals in an arc-shaped disposition; and one of the pairs has a width larger than that of the other pairs.
 11. A fuel tank, comprising: an inner surface; an engaged portion protruding from the inner surface; an in-tank component part; and an engaging portion disposed in the in-tank component part, and engaging inward with an outer periphery of the engaged portion from an outer peripheral side to an inner peripheral side, wherein: both of the engaged portion and the engaging portion deform elastically to engage the engaging portion with the engaged portion, thereby installing the in-tank component part to the fuel tank.
 12. The fuel tank set forth in claim 11, wherein: the engaged portion comprises an engaged rib through which an engaged hole is bored; and the engaging portion comprises an engaging claw engaging with the engaged hole.
 13. The fuel tank set forth in claim 11, wherein the engaged portion is disposed on an inner peripheral side with respect to the engaging portion.
 14. The fuel tank set forth in claim 11, wherein the engaging portion is composed of a material whose fuel-swelling property is less than that of a material composing the engaged portion.
 15. The fuel tank set forth in claim 11 comprising a plurality of pairs of the engaged portion and the engaging portion engaging with engaged portion, the pairs disposed at angular intervals in an arc-shaped disposition; and one of the pairs has a width larger than that of the other pairs. 